Integrating Ecologically Sustainable Water Management into the Saluda Relicensing

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Integrating Ecologically Sustainable Water
Management into the Saluda Relicensing
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Congaree National Park
? Located at confluence of Congaree and Wateree
rivers ? 35 miles downstream of Saluda
Dam/Lake Murray ? South Carolinas only National
Park ? Protects more than 25,000 acres of
forest, including the largest contiguous tract of
old growth bottomland hardwood forest in the
United States ? The floodplain ecosystem, the
park regularly floods several times each year
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Congaree River
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What is ESWM?

• A Five Step Process
• Developed by The Nature Conservancy
• Science-based, stakeholder inclusive, balances
  human and ecological needs
• Steps Include
• 1) Orientation workshop involving multiple
  stakeholders
• 2) Comprehensive literature review, study report
• 3) Technical workshop
• 4) Implementation of flow prescription
• 5) Adaptive management
• Monitoring, research, feedback.

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What is ESWM?

• Emphasis on collaboration adaptive management
  good science balanced approach natural
  interannual variability species based
• Integrate w lake levels, hydro operations and
  other interests
• Successfully used at Savannah River and across
  country

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The ESWM Process
Courtesy TNC Freshwater Initiative
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Congaree ESWM

• First
• Assemble partners (NPS, FWS, American Rivers,
  TNC, Coastal Conservation League, SCEG, and
  others)
• Contracted with USC to conduct a comprehensive
  literature review, produce a study report
• Contracted with USC to develop a floodplain
  inundation model using LIDAR and vegetation data
• Contracted with a professional facilitator.

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Floodplain inundation model
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Modeling Congaree River Flows for ESWM Fish
Spawning Habitat Criteria

• Robust Redhorse fish require
• 0.5 3.7 feet of water flowing over
• gravel point bars for spawning.
• The model indicates that this flow
• depth occurs between 6,000 22,000 cfs

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What we know

• Flood frequency, timing, and duration decreased
  since 1930 when the dam was completed
• A 2-year event is now a 4.5 year event, etc.
• On average 1/3 of Congaree flow is from Saluda
  (2/3 from the relatively unregulated Broad)
• Flood plain community undergoing change in
  composition, particularly decreased recruitment
  on bald cypress

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? Indicator species info? Dependence on
flows/flooding? Available life history
literature? 17 species
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Bald Cypress

• Taxodium distichum
• Deciduous conifer
• Long lived (700 yrs)
• 50 to 70 feet in height with 30 foot spread
• Forms knees
• Dependent on floods for seed dispersal and
  droughts for germination, recruitment

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Redfin Pickerel

• Esox americanus
• Carnivorous
• Have sticky eggs that attach to submerged
  vegetation
• Found in streams, lakes, ponds and backwaters
• Live 7-8 years
• Length 12 inches

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Prothonotary Warbler

• Protonotaria citrea
• Winters in Central and South America
• Males and females have similar appearance
• Breeds in flooded bottomland hardwood forests in
  holes
• Vulnerable to habitat destruction

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Marbled Salamander

• Ambystoma opacum
• 3-5 inches long (adults)
• Breeds in fall on land
• Females guard eggs
• Carnivorous
• Important species in floodplain habitats
• Sensitive to altered hydrology, quality

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Striped Bass

• Morone saxatilis
• Anadromous
• SC State FishSC State Sport Fish
• Predator (carnivorous)
• 20-36 inches long
• 3-10 lbs. average weight(max 60 lbs. -
  freshwater)(max 120 lbs. - saltwater)

• Low rate of hatchling survival reduced egg
  production

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The Technical Workshop

• Invited ologists
• Encouraged other stakeholders to attend
• Goal was to develop a flow recommendations for
  river and floodplain, including inter-annual
  variability as a starting point to an adaptive
  management plan.

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Technical Workshop process
Flood

• EFCs for
• Dry years
• Average years
• Wet years

Modified from TNC
Instream Flow
High Pulse
Low Flow
Flood
Unified Flood
Floodplain Terrestrial
High Pulse
Full Group
Unified High
Low Flow
Unified Low
Flood

• Defined by
• Magnitude
• Frequency
• Timing
• Duration
• Rate of change

Floodplain Aquatic
High Pulse
Low Flow
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What weve learned
? Mean annual flow in Congaree 9,000 cfs ?
Filling of swamp creeks and guts begins at
8,000cfs ? Filling of back swamp areas and
connecting oxbows at 11,000-12,000 cfs ? Levees
topped at 30,000 cfs ? 2-year event 70,000
cfs ? At high flows, flows are driven in greater
proportion by Broad River. ? Saluda Dam
operations netter for enhancing flooding
Image Source K.M.Meitzen
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What weve learned
? Minimum flow needed (mussels) ? Periods of
stable flows/inundation needed (redbreast
sunfish) ? Periods of stable temperatures needed
(e.g. striped bass) ? Periods of desiccation are
likely to be part of the mix (e.g., bald cypress)
Image Source K.M.Meitzen
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What weve learned
? Large floods needed (bald cypress) ? Medium
floods needed (prothonotary warbler) ? Minor
floods needed (marbled salamander) ? Backwater
connectivity needed (redfin pickerel)
Image Source K.M.Meitzen
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Whats next
? Currently drafting an integrated flow
recommendation based on technical workshop ?
Reconvening stakeholders April 21 to build
consensus for flow prescription ? Balancing
downstream flow needs with other interests
Stakeholders FERC license
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Bald cypress gt50,000 cfs 2/yr 3 yr sustained
desiccation events every 20 yrs _at_ lt8,000cfs
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Striped bass, American shad, Robust redhorse Need
stable temps
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Q (in thousands)
Prothonotary warbler 30,000cfs-40,000cfs
Striped bass 9,000cfs descending to 7,000 cfs
Short-nosed sturgeon 17,000 cfs- 26,000 cfs
Marbled salamander
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American shad 7,200cfs-12,500cfs
Robust redhorse 6,00cfs-7,500cfs
Redfin pickerel
Blueback herring gt10,000 cfs
Mussels
1300
1000

700
O N D J F M
A M J J A S
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Robust Redhorse

• Moxostoma robustum
• Long-lived ( 30 years)
• Eats freshwater mussels which it grinds with its
  molar like teeth
• Grows up to 30 inches and can weigh 17 lbs.
• Restricted range
• Reintroductions underway in SC
• Federally listed as a species of concern

Historic range of the Robust Redhorse